A Millimeter-Wave Mobile Broadband (MMB) system is a millimeter wave based system which operates in a radio frequency range between 30 Gigahertz (GHZ) and 300 GHz. An MMB system uses radio waves with a wavelength in the range of 1 millimeter (mm) to 10 mm and is a candidate for next generation mobile communication technology due to the considerable amount of spectrum available in mmWave band.
Generally, in an MMB system, MMB base stations are deployed with higher density than macro-cellular base stations in order to ensure good network coverage. This is possible as transmission and reception of signals is based on narrow beams which suppresses interference from neighboring MMB base stations and extends the range of an MMB link.
Typically, in a MMB network, multiple base stations form a grid with a large number of nodes with which a mobile station can communicate, thereby ensuring high quality Equal Grade Of Service (EGOS) irrespective of the location of the mobile station. The grid having a plurality of base stations serving a mobile station is commonly termed as a virtual cell or a cloud cell. In a could cell, the multiple base stations communicating with a mobile station need to perform downlink transmission beamforming while the mobile station communicating with the base stations needs to perform downlink reception beamforming for receiving downlink control information and data packets. Similarly, a mobile station communicating with a base station in a cloud cell may need to perform uplink transmission beamforming while the base station needs to perform uplink reception beamforming for transmitting uplink data.
Further, in a cloud cell, one base station acts as a master base station and the remaining base stations act as slave base stations with respect to the mobile station. The base stations in the cloud cell serving a mobile station keep changing dynamically based on movement of the mobile station. The cloud cell thus is a user centric virtual cell. In an overlapping cloud cell scenario, a base station can be a part of more than one cloud cell. In one cloud cell, the base station may act as a master base station for one mobile station and in another cloud cell, the same base station may act as a slave base station for another mobile station or the base station can act as a master base station for another mobile station.
One or multiple base stations in a cloud cell may be used to transmit data to a mobile station in a DownLink (DL) direction (i.e., from a base station to a mobile station). The multiple base stations may transmit the same or different data to the mobile station. Similarly in the UpLink (UL) direction, data from the mobile station to a wireless network may be transmitted using one or multiple base stations. In order to receive or transmit data in DL and UL respectively, the mobile station needs to decode control information carrying resource allocation information. That is, the resource allocation information precedes actual transmission of data in DL and UL. The resource allocation information provides details necessary to decode physical layer packets transmitted in the DL or to encode the physical layer packet for transmission in the UL. For example, in an Orthogonal Frequency Division Multiple Access (OFDMA) system, the resource allocation information may include subcarriers and OFDM symbols for which a physical layer packet will span, modulation and coding scheme, power level, MIMO parameters, MS address, etc.
In systems of the related art, the mobile station communicates with a single base station and receives resource allocation information from that base station. Based on the resource allocation information, the mobile station receives and/or transmits data with the base station. However, in a cloud cell, the mobile station has to receive/transmit the same or different data simultaneously from multiple base stations in the cloud cell. Thus, each of the base stations signaling resource allocation information to the mobile station and the mobile station receiving/transmitting data from/to multiple base stations may not be feasible in the cloud cell environment unlike the wireless communication systems of the related art. Accordingly, there is a need for an improved apparatus and method for signaling and processing control information in a cloud cell environment.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.